THE BASIC RELATIONSHIP BETWEEN RESIDUAL （剩余的基本关系）.pdf

Copyright ©JCPDS-International Centre for Diffraction Data 2009 ISSN 1097-0002 336 THE BASIC RELATIONSHIP BETWEEN RESIDUAL STRESS PROFILE PATTERNS AND FATIGUE LIFE OF PRECISION MACHINED SURFACES IN ROLLING CONTACT  Y.B. Guo , A.W. Warren Dept. of Mechanical Engineering, the University of Alabama, Tuscaloosa, AL 35487, USA ABSTRACT The characteristics of residual stress (RS) profiles and their effects on rolling contact fatigue life for precision turned and ground surfaces with a white layer (WL) are very controversial. The key findings of this study are: (a) The basic RS profiles by a sharp tool can be fundamentally changed by a turned WL but not a ground WL; (b) The hook shaped RS profile of a turned surface may have about 40% more fatigue life than a ground one; (c) The white layer may reduce fatigue life as much as 7-8 times despite the deep compressive RS in the subsurface. Keywords : Residual stress, fatigue, surface, machining INTRODUCTION Hard turning and grinding are competitive finishing processes for the production of bearings, gears, cams, etc. The most significant differences in the characteristics of residual stress profiles [1-6] by “gentle” hard turning and grinding are manifested in two aspects: (i) hard turning with a sharp cutting edge geometry (honed or chamfered) generates a “hook” shaped residual stress profile characterized by compressive residual stress at the surface and maximum compressive residual stress in the